Dear Amy: My eldest son, who is 30, and his 21-year-old girlfriend live with my wife and me.

He has a 3-year-old son by this girlfriend, and the child lives with us. She just gave birth to a baby girl who is not my son’s.

I understand that she kept the baby because it was a girl and she wanted to have a girl. I do want to support my son, but we are not sure how to feel about this new development.

My son is dependent on us (mainly my wife). The girlfriend’s family is poor and doesn’t seem to be supportive at all.

Honestly, I don’t know if I want to help raise a child that isn’t even related to us.

I can tell that my son loves his girlfriend, but she doesn’t seem to have the same feelings about him. Is there a better way to deal with the situation, or is it OK to just do what we are doing and see how it goes? — Concerned

Dear Concerned: Let me try to paint a picture of your future: You and your wife will end up with a household of kids of various parentage — along with two adults who are not equipped to support or raise them. That’s what will happen if you continue to “do what you are doing and see how it goes.”

Make sure that you and your wife are on the same page. Assert your own point of view to your son and his girlfriend together. You should make your expectations and the consequences clear.

Your family needs ongoing professional intervention. You should set up a meeting with a social worker and commit to regular meetings, goal-setting and follow-through — for all of you.

You don’t say if your son is able to financially support this growing family, but he and this young mom must work at a trade where they can support the kids.

The girlfriend needs to learn about and use birth control. She has two children at a young age — with each successive pregnancy, her (and her kids’) chances of success will plunge and this pattern will continue.

Dear Amy: A friend told me that my son and daughter-in-law did not send her a thank-you note for a wedding gift. My son has been married for almost two years. Should I say something to my son and daughter-in-law? My friend doesn’t want me to say anything. — Barb

Dear Barb: You should speak to your son and daughter-in-law. You can do so without violating your friend’s confidence.

Simply ask them, “Did you send out all of your thank-you notes for your wedding gifts? If you haven’t thanked people, you should get on it right now.”